Study on Spatial and Temporal Variation of Water Surplus and Deficiency in Yellow River Basin
黄河流域水分亏缺时空格局变化研究

The water surplus and deficiency(WSD) was calculated with precipitation and reference crop evapotranspiration which were calculated with Penman-Monteith method recommended by FAO in 1990,based on climatic data of 93 meteorological stations in the Yellow River Basin(YRB) authorized by the National Climatic Bureau from 1957 to 2001.Meanwhile,the WSD distribution map of the YRB was also generated through the Kriging method.The result shows the spatial distribution of WSD is strongly affected by climatic and geographical factors,and WSD decreases from north to south in the YRB,and from northwest to southeast in the northern part of the YRB.From 1957 to the end of the 1990s,the WSD presented an increasing trend.At the same time,the seasonal variation of WSD was obvious,being more obvious in spring and summer but less in winter and autumn,and with distinct regional variation.